BETHESDA, Md. — At this time a year ago, Jordan Spieth was playing a couple of PGA Tour events for nothing more than experience and gearing up for a summer of amateur golf before returning to Texas for the start of his sophomore season.

Golf is a job now, and it's even more fun.

The 19-year-old Texan describes this summer as "free swinging," and it's not a bad place to be. He started the season in January with no guaranteed place to play, and he already is assured of a PGA Tour card when the new season starts in October.

Now he wants more — a PGA Tour win that would create bountiful opportunities — and the AT&T National would be a good place to start.

Spieth hit all 18 greens in regulation Friday, extended his streak without a bogey to 29 holes at tough Congressional and wound up with a 5-under 66 to share the 36-hole lead with Roberto Castro going into the weekend.

Not everyone has completed 36 holes just yet. Thunderstorms late in the afternoon halted the second round, and the other half of the field was to return Saturday morning to complete the round. Spieth and Castro (69) were at 7-under 135. Andres Romero of Argentina was at 5-under with five holes remaining. No one else was within four shots of the leaders when play was stopped.

Asked what it would mean to win, Spieth said it would be "huge," until showing some maturity.

"I can't really think about that at this point," he said. "It's only halfway through the tournament. So there's a long way to go."

It already feels like a long journey this year.

For a teenager who started the season with no tour to call his own, this is his 14th tournament on the PGA Tour — five more than Tiger Woods — and he already has earned more than $900,000, which is the equivalent of being No. 39 on the tour money list.

But he won't be eligible for the lucrative FedEx Cup playoffs unless he's a PGA Tour member, and he can't be a member this year unless he wins.

"Honestly, I think it's a great position to be in," Spieth said. "I'm just free swinging. I can't be in the playoffs unless I win, and that makes winning the No. 1 goal. You'd like to get in the playoffs and play against the top players, the best players from this year. It's everyone's goal out here to win the FedEx Cup. My goal is to move up the world rankings as much as I can, and that's the way to do it, is to get into those playoffs."

D.H. Lee had a 66 and was two shots behind at 5-under 139. Cameron Tringale (67) and James Driscoll (69) were another shot behind, while the group at 3-under 139 included former British Open champion Stewart Cink (69), Gary Woodland (69) and David Lingmerth, who went from around the cut line to contention with a 65.

Spieth has lived up to the hype he first generated when he played late on Sunday in the Byron Nelson Championship at age 16 and tied for 16th. In one year at Texas, the Longhorns won the NCAA title. And in six months as a pro, he has shown quickly that he belongs.

He already has four top 10s and has special temporary membership, meaning he gets unlimited exemptions. His goal was to somehow get a PGA Tour card for 2013-14 season, and a win would be over the top.

Even so, the teenager who was born just three years before Woods turned pro is savvy to realize the tournament is not even halfway over.

"Now all there's left to do is try and get a win to make the playoffs," he said. "So I'm just going out there trying to win and being aggressive, and hopefully, it will work out for me."

Scoring was slightly better at Congressional, a course that has hosted the U.S. Open three times. Warmer weather in the morning made the ball fly a little farther and shortened the longest PGA Tour course on the mainland.